A novel ion-pair RP-HPLC method for simultaneous quantification of naproxen and esomeprazole in pharmaceutical formulations

A mixed-mode reversed-phase/strong-anion-exchange stationary phase: Analyte-retention stability and application in the analysis of nonsteroidal anti-inflammatory drugs

Mixed-mode reversed-phase/anion-exchange chromatography (RP/AEX) is an effective method for the chromatographic analysis of acidic drugs because it combines reversed-phase chromatography (RP) with anion-exchange chromatography (AEX). However, the result repeatability for the RP/AEX analysis of acidic drugs is frequently compromised by the detrimental effects of residual silanol groups in an RP/AEX stationary phase on peak separation and analyte retention. In this study, an RP/weak-AEX stationary phase with amino anion-exchange groups, Sil-AA, was prepared. Subsequently, an RP/strong-AEX stationary phase, Sil-PBQA, was prepared by replacing the amino groups in Sil-AA with a benzene ring and a benzyl-containing quaternary ammonium salt. The chromatographic behaviors of Sil-PBQA and Sil-AA were compared, and the effect of residual silanol groups on the chromatographic behavior of an RP/AEX stationary phase was evaluated. Residual silanol groups not only caused additional electrostatic interactions for acidic analytes, but also competed with the analytes for the anion-exchange sites in an RP/AEX stationary phase. The effects of different salt-containing mobile-phase systems on the analyte-retention behavior of Sil-PBQA were investigated to develop a method that enhanced the repeatability of the RP/AEX acidic-analyte-analysis results obtained using Sil-PBQA and facilitated the separation of nonsteroidal anti-inflammatory drugs on Sil-PBQA. The ideas presented in this paper can improve the separation of peaks and repeatability of results in the RP/AEX analysis of acidic drugs.

Application of Analytical Tools and Techniques for Estimation of a Proton Pump Inhibitor (Esomeprazole Magnesium Trihydrate): A Comprehensive Review

Objective:

The application of various sophisticated analytical tools and techniques is essential for estimating an active pharmaceutical ingredient present in either biofluids or pharmaceutical dosage forms. Reporting the multiple analytical methods used to quantify esomeprazole magnesium trihydrate, a proton pump inhibitor, is the ultimate goal of this review article.

Evidence acquisition:

This article deals with a detailed discussion of different reported analytical procedures along with their pros and cons and their relevant criteria for quantifying the drug. Various analytical techniques like UV-Visible spectrophotometry, HPLC, HPTLC, hyphenated techniques, etc., are developed to assess the esomeprazole magnesium trihydrate in bulk materials, different pharmaceutical formulations, and biological matrices.

Conclusion:

Literature survey confirmed that the hyphenated techniques and chromatographic techniques are best tools for biological matrices. Spectroscopic methods like UV and visible techniques are widely used for pharmaceutical matrices. All of the reported methods are accurate, precise, cost-effective, and sensitive.

Ionisable substances chromatography: A new approach for the determination of Ketoprofen, Etoricoxib, and Diclofenac sodium in pharmaceuticals using ion - pair HPLC

An ion-pair HPLC method was developed and validated to analyze three of non-steroidal anti-inflammatory drugs (Ketoprofen, Etoricoxib, and Diclofenac sodium) in their pure and pharmaceuticals based on their ionisable characteristics. Cetyltrimethylammonium bromide (Cetrimide) was used as an ion pair reagent since it had not been used before for this purpose. Chromatographic analysis was accomplished using the C18 (250 × 4.6 mm, 5μm) column. Mobile phase consisted of a mixture of 50% Cetrimide 10 - 3 M and 50% acetonitrile to analyze Ketoprofen and Etoricoxib, whereas for Diclofenac sodium, mobile phase was a mixture of 30% Cetrimide 10 - 3 M and 70% acetonitrile. pH value was adjusted if necessary to 10 with ammonium hydroxide. The flow rate was 1mL/min and detection wavelengths were at 254 nm, 234 nm, and 254 nm for Ketoprofen, Etoricoxib, and Diclofenac sodium; respectively under ambient temperature. Retention times ( R t ) were 9.41, 7.34, and 6.66 for Ketoprofen, Etoricoxib, and Diclofenac sodium; respectively. The proposed method was evaluated for linearity, accuracy, precision, and specificity according to ICH guidelines. Ketoprofen, Etoricoxib, and Diclofenac sodium were detected in the following linear ranges: (0.031-0.500mg/mL), (0.007-0.110g/mL), and (0.016-0.250mg/mL); respectively with excellent mean recovery values (98.0-102.0%). RSD% was in an acceptable range (less than 2), proving the precision of the developed method. Specificity was proved in the presence of degradation products. Furthermore, a comparison between the results of this study and the reported HPLC methods indicated that this developed method was better in terms of simplicity, analysis time, and no use of buffers in the mobile phase. In conclusion, the developed method can successfully detect Ketoprofen, Etoricoxib, and Diclofenac sodium quantitatively and qualitatively in their dosage forms without any interference with excipients, making this method valuable, reliable, and practical to be applied in quality control laboratories.

Expired Drugs in the Remote Environment

INTRODUCTION

The British Antarctic Survey Medical Unit works in a very remote area of the world, with several Antarctic bases receiving only a single annual resupply of consumable goods. Pharmaceuticals supplied in this manner will often be approaching or past the end of their nominal shelf life before the following year's resupply. Drugs are transported from the UK via ship; the hold is not temperature controlled, and the ship crosses through the tropics (air temperature 25-30°C for approximately 3 wk). The drugs then must be transported from the ship to the base, often in temperatures substantially below freezing. This study assessed the stability of 5 expired drugs (atropine, nifedipine, flucloxacillin, naproxen, and bendroflumethiazide) returned from Antarctic bases.

METHODS

Drugs were opportunistically obtained and tested using stability-indicating assays.

RESULTS

All tested drugs were stable.

CONCLUSIONS

The results suggest that the studied drugs may be stable beyond expiry, even when not maintained in strictly temperature-controlled conditions.